Method of making anvils for ammunition primers



Feb. 2 ,-1926. 1,571,510

J. A. DICKERMAN METHOD OF MAKING 'ANVILS FOR AMMUNITION'PRIMERS 7 Filed July 5, 1923 v a 20 l4 F INEN TOR. IIOIIISIADICKERI'MH Patented Feb. 2, 1926.

U N l T E isnsia we a a we s It JOHN A. DICKERMAN, F BRIDGEPGRT, CONNECTLICUT, ASSfGIl'O'R T0 REMINGTOIN ARMS COMPANY, Illfl, A COREORATIQN (3F DELAWARE.

METHOD OF MAKING ANVILS FOR AISXMUNITION PRIMERS.

Application filed July 3,

1 0 all whom it may concern:

Be it known that 1, JOHN A. DIoKnnMAN, a citizen of the United States, residing at Bridgeport, in the county of Fairfield and 'the State of Connecticut, have invented new and useful Improvements in Methods of Making Anvils for Ammunition Primers, of which the following is a specification.

This invention relates to primers and has for its main object the provision of a simple and reliable primer which will function with exact uniformity at all times.

Another object of the present invention is the provision of a sensitive primer which will be comparatively simple in construction, cheap to manufacture, assembled with ease and in such a manner that it will not be liable to accidental discharge during transportation or loading operations.

Still another object is the provision of the process or means for manufacturing or constructing anvils for primers which will possess the properties and characteristics above mentioned, the process being designed so as to permit manufacture of anvils in quantities at a low cost.

lVith these ends in view the invention consists in the provision of an anvil for a primer for ammunition and a process for making the anvil, the said primer and anvil having certain details of construction and combinations of parts as will hereinafter be described and pointed out in the claims.

Of the drawings Fig. 1 is an enlarged sectional view of a cartridge shell to which has been applied a primer constructed in accordance with the invention.

Fig. 2 is an enlarged sectional view taken at right angles to the view of Fig. 1.

Fig. 3 is a view partly in section and partly in plan showing the instrumentalities which are used in the first step in the construction of the improved anvils.

Fig. 4 is a view in side elevation showing the appearance of the metal after the first step of the process is completed.

Fig. 5 shows the instrumentalities which are used in the second or final step of manufacture.

Fig. 6 is a top plan view of an anvil which has been made in accordance with the present invention.

Placed within the primer cup and held by frictional or other means is the anvil, the

1923. Serial No. 649,333.

projecting end of which is provided with a central projecting point in immediate contact with the fulminate or other detonating mixture and at a predetermined distance from the bottom of the primer cup. The anvil is provided with the usual flash paswhereby to direct the flame to the ore plosive material in the cartridge upon a discharge of the primer by the percussive action of the firing pin. The flame of the fulminate is directed in such a manner to the detonating charge so as to cause a uniform and rapid ignition.

Referring now more particularly to Fi 1 of the drawings there will be seen a cartridge the cylindrical wall 10 of which contains the usual firing charge, projectile, etc., none of which are shown in the drawings. integral with the wall 10 is a base 11 formed with a central primer pocket 12 holding the primer. A flash passage 13 is formed in the base 11 for communicating the flame from the detonating primer charge to the propellant loaded in the case.

Disposed within the pocket 12 is a primer cup comprising side walls 14 and a bottom 1.5 against which the firing pin is adapted to strike. 1

lhe anvil of the present invention is made of brass, copper, or any other suitable metal or alloy, and is formed with a short cylindrical wall 16 which bears against the inner portion of the primer cup thus retaining the anvil in its proper relation to the primer cup. The anvil portion 17 above the cylindrical edge 16 is substantially conoidal in shape and is provided with two oppositely formed openings 18 for the passage of the flame produced by the ignition of the detonate. The extreme upper portion of the anvil is formed by means, which will hereinafter be described, with a central projecting point 19 which is in immediate contact with the priming mixture 20 placed within the primer cup. For the retention of the printing mixture 20 withinthe cup any means well known in the art may be employed such as tinfoil, celluloid, or as an alternative, a binder may be incorporated either in the mixture or used in any other manner to retain the fulminate in place.

In the manufacture of primers perfect uniformity in the finished article is of the utmost importance. It is especially important that finished primers be uniformly sensitive, so that they can be depended upon to fire in guns having a weak main spring or other defective mechanism, and at the same time, be sufficiently stable to permit of safe handling. packing and shipment. For the purpose of providing a construction permitting of the accurate control of the sensitiveness of the primer the anvil 17 is provided with a sharp point 19'. For a given fulminate mixture, the sensitiveness of the primer will depend on the shape of the point, and the distance between the point 19 of the anvil, and the bottom of the primer cup 15'.

In the manufacture of anvils as hitherto carried out it has been impossible, for reasons which will be pointed out, to accurately control the height of theanvil. Anvils of different height leave gaps of different width between the anvil point and the primer cup, and to avoid the condition that some anvils will be dangerously close to the primer, it has been necessary to make the average distance such (that a sharp and forceful blow on the anvil was necessary to ignite the fulminate. Occasional mis fires were inevitable, and in old guns with weakened main springs. were frequent.

By the practice of my improved method of manufacture anvils of uniform height can be secured, and the distance between the bottom of the primer cup and the anvil as well as the shape of the anvil point can be accurately regulated, thereby permi ting of placing the anvil at such a distance from the primer cup that the fulminate will be ignited by a comparatively weak blow. It is likewise possible by the use of my invention to make sensitive primers without the use of supersensitive and dangerous detonat ing mixtures.

Heretofore in the manufacture of primer anvil-s, the anvil height, which controls the sensitiveness of the primer depended upon the thickness of the metal, the material itself its hardness and the method of forming the anvil proper.

Anvils which have been used heretofore have usually been blanked and formed in one operation, the blanking punch being formed with a conical shaped working end for bending or semi-drawing the metal to form the anvil point. When a material was used which was springy or resilient the metal would tend to resume its original shape, the angle of the point would there fore be less acute and the anvil of less height. Thus the hardness of the particular material directly affects the anvil form and height. Since such anvils varied in point contour and in height there was a considerable. variation in the firing pin blow required to ignite the primer and obviously these primers would occasionally fail to function when used in old guns. Then a sufiiciently sensitive detonate was used to function with such primers it was found to be too sensitive for other primers or to permit of safe handling.

These points were objectionable from a commerical viewpoint and one of the objects of the present invention is to provide means for overcoming the objections, and to greatly increase the sensitiveness and uniformity of function of primers without requiring the use of super-sensitive primermixtures. The process or means whereby anvils are constructed and formed in accordance with the present invention is illustrated in Figs. 3, 4t, and 5, reference character 21 denoting the sheet metal from which the anvils are formed.

The punch 22 for pointing the anvils is formed with a cylindrical portion 23 and a conoidal end 24 hardened sufficiently so as to permit the swaging of the metal sheet 21 to the desired shape. The die 25 with which the punch 22 coacts is placed in a suitable holder 27 and is provided with a conical depression 26 the angle of which is shown greater than the angle of the conoidal portion 24. Below the conical depression 26 is a circular aperture 271 for forming the anvil point 19.

During the first step of operation the metal 21 is placed immediately above the die 25, the pointing punch 22 being brought to bear downwardly upon the metal 21 with a great force. The point 241- of the punch 22 will cause the formation of the anvil point 19 and a conoidal portion 28 on the underside of the metal 21 as best shown in Fig. 4. After each pointing operation the metal 21 is fed to the right, the cycle of events being repeated thereby swaging another anvil point injuxtaposition to the one just formed. It will be self-evident that each point is swaged into the desired shape and since each is die-pointed the height will remain constant resulting in a point uniform in contour and height. It will also be quite obvious that the hardness, thickness or resiliency of the metal will have no effect upon the anvil form or height, such as would occur if the point had been formed by a bending or drawing operation.

After the points have been formed in the metal the next step in the operation is that of blanking the metal to the desired shape. This step is illustrated in Fig. 5.

In this view reference character 30 designates the blanking punch formed with two longitudinal grooves 31 forforming the flash passages 18 of the anvil. The lower end 32 of the punch is suitably formed so as to blank the anvil to the desired form. The die 33 is held in a suitable holder 34: and is apertured at 85, the configuration of the aperture corresponding to the profile of the blanking punch 30 with which it coacts.

The aperture isenlarged to a circular hole 36 through which drops the blanked anvils.

In this step of manufacture the metal 21 is placed directly over the die 33 the projections l9 and 28 extending into the aperture of the die. The blanking punch is next brought to bear upon the metal, shearing or blanking the anvil to the desired profile and forming it with the cylindrical edges 16 hereinbe'lore mentioned, but allecting in no wise the anvil point 19 or 28. Fig. 5 shows an anvil in the die 33 after it has been blanked by the punch 30 and upon a subsequent operation this particular anvil will be forced out of the die 33 through the circular aperture 36 and into a receptacle below. After the anvils have been formed they are placed within the primer cups which have been loaded with a primer charge, and upon the completion of this assembly operation they are inserted in the cartridge shells as hereinbefore stated.

In this method of manufacture it has been possible tosecure anvil points which are exact and uniform in height, the swaging operation being capable of being modified in such a manner that by the employment of different sized punches and dies, anvils of different dimensions and heights may be manufactured. Thus it is possible to control the sensitiveness of the primers and be able to furnish primers which require varying degrees of sensitiveness depending upon r the conditions imposed upon them.

\Vhile there has been described a specific embodiment of the invention such as shown in the drawings and one method of the process or means for making primers in accordance with the present invention, it is to be understood that the details of construe tion or steps in the process might be readily varied by atperson skilled in the art without departing from the spirit of the invention.

hat is claimed is as follows:

1. The method of making anvils for ammunition primers which comprises the steps of swaging the anvil point from a sheet of stock in a swaging machine, and cutting the anvil from said sheet stock in a separate subsequent operation of the machine.

2. The method of making anvils for ammunition primers from sheet stock which comprises the steps of cold swaging the anvil point to a shape while the periphery of the anvil forming material is connected with the sheet and striking the anvil from the sheet in a subsequent separate operation.

3. The method of making anvils for am munition primers from sheet stock which comprises the steps of cold swaging in said sheet under a swaging die a relatively sharp conical projection, advancing said sheet to ause said projection to register with a blanking die, and striking from said sheet by means or said blanking die an anvil oi? the desired contour.

In Witness whereof l have signed my name hereto this 30th day 01' June, 1923.

JOHN A. DIGKERMAN.

Certificate of Correction.

It is hereby certified that in Letters Patent No. 1,571,510, granted February 2, 1926, upon the application of John A. Dickerman, of Bridgeport, Connecticut, for an improvement in Methods of Making Anyils for Ammunition Primers, an

error appears in the printed specification requlrlng correction as follows: Page 3, line 55, claim 2, strike out the article a and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 16th day of March, A. D. 1926.

[SEAL] 'M. J. MOORE,

Acting Conwm'ssz'oner of Patents. 

